Volume: 2, 2023
2nd International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: T033
DOI: https://doi.org/10.24326/ICDSUPL2.T033
Published online: 19 April 2023
ICDSUPL, 2, T033 (2023)
Studies of selected switching parameters of electric power vacuum interrupters
Michał Lech1*, Paweł Węgierek1
1 Department of Electrical Devices and High Voltage Technology, Faculty of Electrical Engineering and Computer Science, Lublin University of Technology, Nadbystrzycka 38A, Lublin, Poland
* Corresponding author: m.lech@pollub.pl
Abstract
The use of vacuum technology is taking place in many industries and the economy. Over the past decades, in the electric power industry, vacuum has gained its recognition as an insulating medium used in switching and distribution apparatus. In the 1980s, oil was the dominant insulating medium, with about 65% of newly designed medium-voltage circuit breakers using this type of insulation. Currently, almost 100% of newly designed MV circuit breakers are based on vacuum insulation. Therefore, it is necessary to develop new solutions to improve the performance of power vacuum apparatus. The paper presents the position, methodology and results of measurements of selected switching parameters of vacuum interrupters used in modern medium and high voltage switchgear. We are talking about the electrical strength of the contact gap, energy of the vacuum arc, or its burning time. The values of the vacuum breakdown voltages of the insulation system were measured for different values of pressure and type of residual gases. Two characteristic ranges of the obtained results were observed. In the first, the vacuum interrupter filled with the selected gas maintains a constant value of electrical strength, regardless of the pressure inside. The value of the breakdown voltage is affected only by the contact gap. The larger its value, the breakdown voltage also increases. Once the pressure limit in the discharge chamber is exceeded, the electrical strength of the system rapidly decreases and the contact system loses its insulating properties. For residual gas in the form of helium, the insulating capacity is maintained for the largest pressure range. The value of the arc energy depending on the time of its triggering after the current sinusoid passes through zero was also measured. It was found that the highest arc energy occurs when the contacts are opened about 1-2 seconds after the current sinusoid passes through zero. In further steps, the arc energy was measured for pressures ranging from 1E-3 Pa to 1E5 Pa, triggering the opening of the contacts in such a way that the arc energy was highest. It was observed that below a pressure of 2E-1 Pa, the arc energy remains constant, while above this value the arc energy increases in a logarithmic manner.
How to cite
M. Lech, P. Węgierek, 2023. Studies of selected switching parameters of electric power vacuum interrupters. In: 2nd International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL2.T033